1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
SIZIF [17.4K]
3 years ago
9

The process of how rocks can tell us how old the earth is

Physics
1 answer:
Ludmilka [50]3 years ago
7 0
The Earth is a constantly changing planet. Its crust is continually being created, modified, and destroyed. As a result, rocks that record its earliest history have not been found and probably no longer exist. Nevertheless, there is substantial evidence that the Earth and the other bodies of the Solar System are 4.5-4.6 billion years old, and that the Milky Way Galaxy and the Universe are older still. The principal evidence for the antiquity of Earth and its cosmic surroundings is:The oldest rocks on Earth, found in western Greenland, have been dated by four independent radiometric dating methods at 3.7-3.8 billion years. Rocks 3.4-3.6 billion years in age have been found in southern Africa, western Australia, and the Great Lakes region of North America. These oldest rocks are metamorphic rocks but they originated as lava flows and sedimentary rocks. The debris from which the sedimentary rocks formed must have come from even older crustal rocks. The oldest dated minerals (4.0-4.2 billion years) are tiny zircon crystals found in sedimentary rocks in western Australia.
The oldest Moon rocks are from the lunar highlands and were formed when the early lunar crust was partially or entirely molten. These rocks, of which only a few were returned by the Apollo missions, have been dated by two methods at between 4.4-4.5 billion years in age. 
The majority of the 70 well-dated meteorites have ages of 4.4-4.6 billion years. These meteorites, which are fragments of asteroids and represent some of the most primitive material in the solar system, have been dated by 5 independent radiometric dating methods. 
The "best" age for the Earth is based on the time required for the lead isotopes in four very old lead ores (galena) to have evolved from the composition of lead at the time the Solar System formed, as recorded in the Canyon Diablo iron meteorite. This "model lead age" is 4.54 billion years. 
The evidence for the antiquity of the Earth and Solar System is consistent with evidence for an even greater age for the Universe and Milky Way Galaxy. a) The age of the Universe can be estimated from the velocity and distance of galaxies as the universe expands. The estimates range from 7 to 20 billion years, depending on whether the expansion is constant or is slowing due to gravitational attraction. b) The age of the Galaxy is estimated to be 14-18 billion years from the rate of evolution of stars in globular clusters, which are thought to be the oldest stars in the Galaxy. The age of the elements in the Galaxy, based on the production ratios of osmium isotopes in supernovae and the change in that ratio over time due to radioactive decay, is 8.6-15.7 billion years. Theoretical considerations indicate that the Galaxy formed within a billion years of the beginning of the Universe. c) Combining the data from a) and b), the "best, i.e., most consistent, age of the universe is estimated to be around 14 billion years. For more current information on the age of the universe.
You might be interested in
Which of the following statements correctly describes the index of refraction of a material? Select all that apply.
mote1985 [20]

Answer:

Option C and D only

Explanation:

Option A is incorrect  because refractive index of a material is the ratio of speed of light in vacuum to the speed of light in a any given medium

Option B is correct as the speed of light in vacuum is always greater than the speed of light in any given medium.

Option C is correct

Option D is incorrect

Option E is incorrect because the denser the medium the more is the refractive index. Water is denser than air, hence it should have more refractive index as compared to that of air.

4 0
2 years ago
If I push on the wall with 75 Newtons of force, the wall will push back with __
Scilla [17]

Answer: 0

Explanation:

75 newtons will push back canceling it out make it 0

7 0
3 years ago
The strength of the gravitational pull between two object's is determined by?
iogann1982 [59]
Mass and distance are the two factors
4 0
3 years ago
Read 2 more answers
A radio has a 1.3 A current. If it has a resistance of 35 Ω, what is the potential difference?
DedPeter [7]

Answer:

22

Explanation:

7 0
3 years ago
Read 2 more answers
An object is projected with initial speed v0 from the edge of the roof of a building that has height H. The initial velocity of
Vsevolod [243]

Answer:

Explanation:

Initial velocity u = V₀ in upward direction so it will be negative

u = - V₀

Displacement s = H . It is downwards so it will be positive

Acceleration = g ( positive as it is also downwards )

Using the formula

v² = u² + 2 g s

v² = (- V₀ )² + 2 g H

= V₀² + 2 g H .

v = √ ( V₀² + 2 g H )

6 0
3 years ago
Other questions:
  • Tectonic plates are large segments of the earth's crust that move slowly. Suppose one such plate has an average speed of 6.0 cm
    5·1 answer
  • A good thesis statement does all of the following
    13·2 answers
  • The discussion of the electric field between two parallel conducting plates, in this module states that edge effects are less im
    12·1 answer
  • An object with a mass of 2 kilograms is accelerated at 5 m/s2.
    12·2 answers
  • One strategy in a snowball fight is to throw
    6·1 answer
  • A circular loop of wire with a radius of 12.0 cm and oriented in the horizontal xy-plane is located in a region of uniform magne
    12·1 answer
  • Maximum power transfer theorem iz related to which chapter of physics<br> Class 12
    13·1 answer
  • A spotlight on the ground shines on a wall 15 meters away. A man 1.8 meters tall walks away from the spotlight toward the buildi
    6·1 answer
  • Which of the following element has seven total valence electrons? Your answer: argon helium oxygen bromine
    8·1 answer
  • When an object is lifted 12 meters off the ground, it gains a certain amount of potential energy. If the same object is lifted 2
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!